Preparation of peracetic acid by oxidation of acetaldehyde

Abstract

This specification discloses a vapor phase process for oxidizing acetaldehyde to peracetic acid, acetic acid being formed as an additional product. Oxygen is used as the oxidizer at concentrations of less than 10% by using excess acetaldehyde and diluting the reaction with recycle gas. Initial mixing of the oxygen with acetaldehyde is done in an explosion-suppression chamber prior to introducing the reaction mixture into a reactor.

What is claimed is: 
     
       1. In the process of producing peracetic acid by the vapor-phase oxidation of acetaldehyde in a reaction zone, in which the reactants, acetaldehyde and oxygen, are mixed before introducing the reaction gas mixture into the reaction zone, which is maintained at a temperature of 100° to 230° C at a pressure of up to 50 pounds per square inch, and recovering the product peracetic acid by absorption in a liquid selected from the group consisting of acetone and ethyl acetate, the improvement which comprises: (a) mixing the reactants in a cylindrical mixer-explosion-suppression chamber containing aluminum or stainless steel packing whose passage diameter is less than the critical diameter of the reaction gas mixture, while maintaining the oxygen concentration at less than 10% by volume in said chamber and maintaining the reaction gas velocity in the explosion suppression chamber in excess of the flame velocity of the reaction gas mixture, and (b) introducing the mixed reaction gas mixture into the reaction zone, in which the oxygen concentration in the reaction zone is maintained at less than 10% by volume of the reaction gas mixture. 
     
     
       2. The process of claim 1 in which the reactants are mixed at below 50° C and the reaction temperature is 140° to 180° C. 
     
     
       3. The process of claim 1 in which the absorbing liquid for the peracetic acid is first vaporized and then fed to the bottom of the absorber.